JPH0626434B2 - Image processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image processing apparatus for synthesizing a color image including a halftone image and a line image such as a character image to obtain a color image.

2. Description of the Related Art Conventionally, as an image processing apparatus configured to perform halftone reproduction using a dot image, an apparatus based on an inkjet printer method, a thermal transfer printer method, a laser beam printer method, or the like is known. In such an apparatus, various halftone processing methods are adopted to reproduce halftone.

Further, there are cases where it is desired to combine a dot pattern such as a character or a specific line pattern with the halftone image as described above.

In such a synthesis, for example, in the case of monochrome image synthesis, it can be easily performed by taking a logical sum of a monochrome halftone image and a dot pattern.

However, in order to synthesize the color halftone image and the dot pattern of a desired color, for example, in the plate making technique for printing, the plates for the respective colors Y, M, C and Bk of the color halftone image and A complicated process such as creating a plate with a dot pattern of a desired color separately, optically synthesizing these plates manually instead of electrically, and finally creating a plate for printing It was necessary, and there was a problem that it was difficult to do it accurately.

Further, such plate-making technology was not immediately applicable to color printing technology.

[Object of the Invention]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an image processing apparatus that can electrically and easily combine a color image and a desired color dot pattern at high speed.

To this end, the present invention provides an image processing apparatus for a color printer (corresponding to FIGS. 1 to 5 in the embodiment) that forms an image of a plurality of color components according to a predetermined sequence. First supply means for supplying color image information to be imaged by the printer for each color component in accordance with the predetermined sequence (corresponding to transfer from the dither processing circuit 24 of FIG. 1 to the image memory 21 in the embodiment). A memory in which pattern information different from the color image information is stored as a dot pattern (similarly 8), means for storing a predetermined dot pattern in the memory (also corresponding to the writing position designating circuit 15), Generating means for generating designation information for designating the color of the dot pattern (also corresponding to a signal inputted from line 120); Second supplying means (also 14) for supplying the formed dot pattern to the color printer, the dot pattern is colored according to the designation information without changing a predetermined sequence of the color printer, and the color image information is obtained. The second supply corresponding to the type of the color component of the color image information and the type of the color component of the designation information supplied by the first supply unit according to the predetermined sequence. Synthesizing means (also OR gate 7, control circuit 16) for electrically synthesizing the dot pattern supplied by the synthesizing means, and imparting means for imparting the signal synthesized by the synthesizing means to the color printer in accordance with the predetermined sequence. (Also the line buffer 6).

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing an entire embodiment of the present invention.
In the illustrated image processing apparatus, a character code string signal as shown in FIG. 2 is used as the character image data 101, and R, G, B color identification signals 104 as shown in FIG. , Horizontal sync signal 106V, 10
The image signal 105 accompanied by 6H is supplied from the outside. Further, the image trimming position designation signals 102, 103, 1
07 and 108 are also supplied from the outside.

FIG. 2 shows a character image data string signal, which contains the character string data C ₁₀ , C ₁₁ , C ₁₂ ---- in the first row following the leading identification code ITOP of one image. Further, the RET code is inserted after the last character of each line. Therefore, R on the receiving side (that is, the image processing apparatus side)
When the ET code is detected, a line feed is performed. In FIG. 2, R ₁ is the RET code on the first line, R ₂ is the second
It is the RET code of the line. The end code IEND of the one-character image is inserted next to the last line in the one-character image to end the one-character image data. In the image processing apparatus, the end of one character image is identified by receiving this IEND code.

The character image data 101 supplied as described above is stored in the character code buffer 10 for one screen. At this time,
The above-mentioned special code (for example, ITOP code, RET code, IEND code) is decoded by the character code decoder 11, and the storage start / line feed command signal 109 and the storage end signal 110 for storing the character image are transmitted.

FIG. 4 shows an example of the character screen thus stored. Here, each character A, B, ---- a, b, c, ---- is represented by, for example, an 8-bit ASCII code. Since the image processing apparatus employs a laser beam method using a dot image, it is necessary to convert the above-mentioned character code string into a dot shape. Therefore, in the present embodiment, the dot conversion is performed using the character generator 9. Since the character generator 9 is the same as the well-known one, its explanation is omitted. At this time, the area information signal 102 indicating which area of the one-character image supplied from the outside should be printed out.
(That is, the information that specifies the row and column of the character code image)
Is given from an external device.

For example, in the character code image shown in FIG. 4, the printout start character and end character are (m ₁ , n ₁ ) to (m ₂ ,
When given by n ₂ ), the area within the illustrated bold line is read from the character code buffer 10. The printout designation information (m ₁ , n ₁ ) included in the area information signal 102,
Upon receiving (m ₂ , n ₂ ), the read position designating circuit 17 and the read address generator 18 generate the read address of the designated area.

On the other hand, the designation signal 103 designates a region of the print image where the character image region designated as described above should be printed out. The writing area for printout is given by the pixel number at the writing start position, the scanning line number (m ₁ ′, n ₁ ′), and the same number at the writing end position (m ₂ ′, n ₂ ′). A write address for the image memory 8 is generated by the write position designation control circuit 15 and the image memory address generator 14.

The character code image in the specific area read from the character code buffer 10 in this manner is converted into dot data by the character generator 9 and stored in the designated area in the image memory 8 to be printed out. This state is shown in FIGS. 5A and 5B.

Next, the processing of the color halftone image supplied as the density data of each color of R, G and B will be described. As shown in FIG. 3, this color halftone image has R, G, B color identification signals 10
4, vertical and horizontal synchronizing signals 106V and 106H, and density data for each pixel of the image (that is, image signal)
And 105. Each color image has a buffer memory 28-for each color according to the R, G, B color identification signals 104.
1, 28-2 and 28-3, respectively.

The synchronizing signals 106V and 106H are supplied to the storage address generator 32, and the address selector 30 supplies the necessary addresses to the image buffer memories 28-1 and 28-2.
8-2, 28-3. Thus, each color image is stored in the image buffer memories 28-1, 28-2, 28-3.
Stored in each.

After that, similarly to the reading from the character code buffer 10, the area 107 in which the halftone image is to be printed out is designated by the signal 107 supplied from the outside. this is,
It is given with a printout start point, a pixel number, and a scanning line number, and the corresponding image memories 28-1, 28-
2, 28-3 addresses are generated from the read address generator 31.

At the time of reading, image buffer memory 28-1 for yellow (Y) (stores B signal) 28-1, image buffer memory for magenta (M) (stores G signal) 28-2, cyan (C) The same pixel is simultaneously read out as Y, M, and C components from the image buffer memory (stores the R signal) 28-3. (Here, the complements of the B, G, and R signals are taken and output as Y, M, and C signals.) The color signals thus read out are
Finally, it is stored in the image memory 21 for the halftone image, but by the signal 108 supplied from the outside not shown so that the designated image area is printed out at the designated position as described above. , The write start position is specified. In response to this, the image memory write position designating circuit 23 and the image memory address generator 22 cause the image memory 21 corresponding to the designated position.
Generate the address. This operation is similar to the case of the character image data described above.

The image buffer memories 28-1, 28-2, 2
The color density data for each pixel read from 8-3 is subjected to gamma conversion (density conversion) in accordance with the characteristics of the image processing apparatus in the gamma correction circuit 27, and further masking processing (known in the printing technical field). 26) and UC
After undergoing the R process (see 25) and then the dither process (see 24), it is stored as dot data at the specific position in the image memory 21 designated as described above.
Here, the dither processing is, as is well known, an electric processing for determining a print dot to be output by comparing density data of each pixel with a threshold value in order to reproduce a halftone.

The image processing apparatus sequentially prints out a yellow image first, a magenta image second, a cyan image third, and a black image fourth, and superimposes each color image on top of each other to obtain a full-color image. Therefore, the storage capacity of the image memory 21 is sufficient for one image. Then, each time each color is printed, the above-described color processing and transfer to the image memory 21 are performed.

In order to read the data from the image memory 8 for character images and the image memory 21 for halftone images and send it to the laser light modulation circuit 5, these image data are stored as dot data in the image memories 8 and 21, respectively, and The same address is assigned to the same pixel. In this embodiment, the addressing of both image memories 8 and 21 is controlled by the image memory address generator 14. That is, a read address is generated at the time when an image is stored in both the image memories 8 and 21, so that dot data of a character and a halftone image corresponding to the same pixel is transmitted.

The dot data read from the image memories 8 and 21 is superimposed by the OR gate 7 to modulate the laser light. The modulated laser light forms an electrostatic latent image on the photosensitive drum 1. The process of creating a print image is the same as that of a normal laser beam printer, and Y, M, C, Bk
Four types of developing devices (not shown) are selectively used for (black). Further, a signal 113 is a horizontal synchronizing signal sent from the laser beam detector 40 when the laser beam is applied to the laser beam detector 40, and causes the image memories 8 and 21 to read out image data synchronously.

FIG. 1 120 shows a 4-bit signal that specifies the color of a character image. This signal may be a signal from the host or a switch in the image processing apparatus. Here, each bit of the 4-bit color designation signals C _{0 to} C ₃ is sequentially set to Y, M, C,
It corresponds to Bk. A character image of a desired color can be obtained by controlling the character image output by the latent image forming signal 112 of the color corresponding to the designated bit.
For example, (C ₀ , C ₁ , C ₂ , C ₃ ) = ( ₁ , ₁ , ₀ ,
0), the character image is output when Y and M, and the character becomes a red image.

In general, when a character image is combined with black Bk, the character image clearly appears in the halftone image more effectively. In this case, the color designation signals (C ₀ , C ₁ , C ₂ , C ₃ ) are (0,
0,0,1).

FIG. 5 shows an example in which the designated areas of the character image and the halftone image are individually moved and the two images are combined. That is, the regions are moved with respect to the input images A and C, respectively, and the obtained images B and D are obtained.
To obtain an image B + D.

As described above, according to this embodiment, it is possible to combine a character image with a halftone image without impairing the sharpness of the character image, and to move the designated area separately for each of the character image and the halftone image. Since it can be performed, it is possible to efficiently rearrange and synthesize a character image and a halftone image.

Further, according to the present invention, since the character image can be input using the code, it is possible to connect with other equipment, and it is possible to obtain a versatile image processing apparatus.

Further, according to the present embodiment, the character image can be any color according to the halftone image which is the background,
The reproducibility of the character image and the halftone image can be improved.

As described above, according to the present invention, a colored dot pattern and another color image information are electrically combined without changing the predetermined sequence of a color printer that forms an image of a plurality of color components in accordance with a predetermined sequence. As a result, the high-speed synthesis can be performed and the control can be simplified. Further, since the color image information and the dot pattern are combined independently for each color component, the combination can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire embodiment of the present invention, FIG. 2 is a diagram showing an example of character image data, FIG. 3 is a diagram showing an example of color image data, and FIG. 4 is a character code buffer. FIG. 5 is a diagram showing an example of the stored character screen, and FIG. 5 is a diagram showing an example in which the designated areas of the character image and the halftone image are moved separately and the two screens are combined. 1 ... Photosensitive drum, 2 ... Lens, 3 ... Reflective mirror, 4 ... Laser light source, 5 ... Laser light modulation circuit, 6 ... Line buffer, 7 ... OR gate, 8 ... Character image memory, 9 ... Character・ Generator 10 …… Character code buffer 11 …… Character code decoder 12 …… Interface 14 …… Image memory / address generator 15 …… Image memory writing position designating circuit 16 …… Control circuit 17 …… Reading position designating circuit 18 …… Read address generator 19 Write address generator 20 Address selector 21 Image image memory for halftone images 22 Image memory address generator 23 Image memory write position designation circuit 24 Dither circuit 25 ... UCR Circuit 26 ... Trout King circuit 27 …… Gamma correction circuit 28-1,28-2,28-3 …… Image buffer memory 29 …… Interface 30 …… Address selector 31 …… Read address generator 32 …… Write address generator 33 …… Read position Designated circuit

Claims (1)

[Claims] 1. An image processing apparatus for a color printer which forms an image of a plurality of color components according to a predetermined sequence, wherein color image information to be formed by the color printer is color-coded in accordance with the predetermined sequence. First supply means for supplying each component, a memory in which pattern information different from the color image information is stored as a dot pattern, means for storing a predetermined dot pattern in the memory, and a color of the dot pattern is designated Generating means for generating designation information; second supplying means for supplying the dot pattern stored in the memory to the color printer; and corresponding to the dot pattern according to the designation information without changing a predetermined sequence of the color printer. In order to colorize and combine with the color image information, the first sequence is performed according to the predetermined sequence. Synthesis for electrically synthesizing the dot pattern supplied by the second supply means corresponding to the type of color component of the color image information supplied by the supply means and the type of color component of the designation information An image processing apparatus comprising: a means for applying the signal synthesized by the synthesizing means to the color printer in accordance with the predetermined sequence.